Prevalence of major enteric parasites in children 2-5 years of age in urban Dhaka is around 78%. To see the effects of anti-parasitic drug therapy prior to cholera and typhoid vaccination, we will enroll 102 children in each group in Dukoral (n=102x2=204) and and another 102 children in each group for Vivotif vaccine (102 x 2 = 204). For each vaccine, one group will be treated while another will not be. Thus we plan to study a total of 408 children to determine effect of anti-parasitic drugs on the immune responses to oral cholera and typhoid vaccines.